Noninvasive approaches for early detection of bladder cancer are actively being investigated. We recently developed a urine- based molecular assay for the detection and surveillance of bladder ...neoplasms (UroSEEK). UroSEEK is designed to detect alterations in 11 genes that include most common genetic alterations in bladder cancer. In this study, we analyzed 527 cases, including 373 noninvasive and 154 invasive urothelial carcinomas of bladder from transurethral resections or cystectomies performed at four institutions (1991-2016). Two different mutational analysis assays of a representative tumor area were performed: first, a singleplex PCR assay for evaluation of the TERT promoter region (TERTSeqS) and second, a multiplex PCR assay using primers designed to amplify regions of interest of 10 (FGFR3, PIK3CA, TP53, HRAS, KRAS, ERBB2, CDKN2A, MET, MLL, and VHL) genes (UroSeqS). Overall, 92% of all bladder tumors were positive for at least one genetic alteration in the UroSEEK panel. We found TERT promoter mutations in 77% of low-grade noninvasive papillary carcinomas, with a relatively lower incidence of 65% in high-grade noninvasive papillary carcinomas and carcinomas in situ; p = 0.017. Seventy-two percent of pT1 and 63% of muscle-invasive bladder tumors harbored TERT promoter mutations with g.1295228C>T alteration being the most common in all groups. FGFR3 and PIK3CA mutations were more frequent in low-grade noninvasive papillary carcinomas compared with high-grade noninvasive papillary carcinomas and carcinomas in situ (p < 0.0001), while the opposite was true for TP53 (p < 0.0001). Significantly higher rates of TP53 and CDKN2A mutation rates (p = 0.005 and 0.035, respectively) were encountered in muscle-invasive bladder tumors compared with those of pT1 stage. The overwhelming majority of all investigated tumors showed at least one mutation among UroSEEK assay genes, confirming the comprehensive coverage of the panel and supporting its potential utility as a noninvasive urine-based assay.
Cell-free DNA shed by cancer cells has been shown to be a rich source of putative tumor-specific biomarkers. Because cell-free DNA from brain and spinal cord tumors cannot usually be detected in the ...blood, we studied whether the cerebrospinal fluid (CSF) that bathes the CNS is enriched for tumor DNA, here termed CSF-tDNA. We analyzed 35 primary CNS malignancies and found at least one mutation in each tumor using targeted or genome-wide sequencing. Using these patient-specific mutations as biomarkers, we identified detectable levels of CSF-tDNA in 74% 95% confidence interval (95% CI) = 57−88% of cases. All medulloblastomas, ependymomas, and high-grade gliomas that abutted a CSF space were detectable (100% of 21 cases; 95% CI = 88−100%), whereas no CSF-tDNA was detected in patients whose tumors were not directly adjacent to a CSF reservoir (P< 0.0001, Fisher’s exact test). These results suggest that CSF-tDNA could be useful for the management of patients with primary tumors of the brain or spinal cord.
Activating mutations occur in the promoter of the telomerase reverse transcriptase (TERT) gene in 66% of muscle-invasive urothelial carcinomas. To explore their role in bladder cancer development and ...to assess their utility as urine markers for early detection, we sequenced the TERT promoter in 76 well-characterized papillary and flat noninvasive urothelial carcinomas, including 28 pTa low-grade transitional cell carcinomas (TCC), 31 pTa high-grade TCCs, and 17 pTis carcinoma in situ lesions. We also evaluated the sequence of the TERT promoter in a separate series of 14 early bladder neoplasms and matched follow-up urine samples to determine whether urine TERT status was an indicator of disease recurrence. A high rate of TERT promoter mutation was observed in both papillary and flat lesions, as well as in low- and high-grade noninvasive urothelial neoplasms (mean: 74%). In addition, among patients whose tumors harbored TERT promoter mutations, the same mutations were present in follow-up urines in seven of eight patients that recurred but in none of the six patients that did not recur (P < 0.001). TERT promoter mutations occur in both papillary and flat lesions, are the most frequent genetic alterations identified to date in noninvasive precursor lesions of the bladder, are detectable in urine, and seem to be strongly associated with bladder cancer recurrence. These provocative results suggest that TERT promoter mutations may offer a useful urinary biomarker for both early detection and monitoring of bladder neoplasia.
Rare circulating tumor cells (CTCs) present in the bloodstream of patients with cancer provide a potentially accessible source for detection, characterization, and monitoring of nonhematological ...cancers. We previously demonstrated the effectiveness of a microfluidic device, the CTC-Chip, in capturing these epithelial cell adhesion molecule (EpCAM)-expressing cells using antibody-coated microposts. Here, we describe a high-throughput microfluidic mixing device, the herringbone-chip, or “HB-Chip,” which provides an enhanced platform for CTC isolation. The HB-Chip design applies passive mixing of blood cells through the generation of microvortices to significantly increase the number of interactions between target CTCs and the antibody-coated chip surface. Efficient cell capture was validated using defined numbers of cancer cells spiked into control blood, and clinical utility was demonstrated in specimens from patients with prostate cancer. CTCs were detected in 14 of 15 (93%) patients with metastatic disease (median = 63 CTCs/mL, mean = 386 ± 238 CTCs/mL), and the tumor-specific TMPRSS2-ERG translocation was readily identified following RNA isolation and RT-PCR analysis. The use of transparent materials allowed for imaging of the captured CTCs using standard clinical histopathological stains, in addition to immunofluorescence-conjugated antibodies. In a subset of patient samples, the low shear design of the HB-Chip revealed microclusters of CTCs, previously unappreciated tumor cell aggregates that may contribute to the hematogenous dissemination of cancer.
Glioblastoma (GBM) is a highly aggressive brain cancer characterized by local invasion and angiogenic recruitment, yet metastatic dissemination is extremely rare. Here, we adapted a microfluidic ...device to deplete hematopoietic cells from blood specimens of patients with GBM, uncovering evidence of circulating brain tumor cells (CTC). Staining and scoring criteria for GBM CTCs were first established using orthotopic patient-derived xenografts (PDX), and then applied clinically: CTCs were identified in at least one blood specimen from 13 of 33 patients (39%; 26 of 87 samples). Single GBM CTCs isolated from both patients and mouse PDX models demonstrated enrichment for mesenchymal over neural differentiation markers compared with primary GBMs. Within primary GBMs, RNA in situ hybridization identified a subpopulation of highly migratory mesenchymal tumor cells, and in a rare patient with disseminated GBM, systemic lesions were exclusively mesenchymal. Thus, a mesenchymal subset of GBM cells invades the vasculature and may proliferate outside the brain.
GBMs are locally invasive within the brain but rarely metastasize to distant organs, exemplifying the debate over "seed" versus "soil." We demonstrate that GBMs shed CTCs with invasive mesenchymal characteristics into the circulation. Rare metastatic GBM lesions are primarily mesenchymal and show additional mutations absent in the primary tumor.
Activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene are the most common genetic alterations in urothelial carcinoma (UC) of the bladder and upper urinary tract. ...Although the cadherin 1 (CDH1) gene is commonly mutated in the clinically aggressive plasmacytoid variant of urothelial carcinoma (PUC), little is known about their TERT promoter mutation status. A retrospective search of our archives for PUC and UC with plasmacytoid and/or signet ring cell features (2007-2014) was performed. Ten specimens from 10 patients had archived material available for DNA analysis and were included in the study. Intratumoral areas of nonplasmacytoid histology were also evaluated when present. Samples were analyzed for TERT promoter mutations with Safe-SeqS, a sequencing error-reduction technology, and sequenced using a targeted panel of the 10 most commonly mutated genes in bladder cancer on the Illumina MiSeq platform. TERT promoter mutations were detected in specimens with pure and focal plasmacytoid features (6/10). Similar to conventional UC, the predominant mutation identified was g.1295228C>T. In heterogeneous tumors with focal variant histology, concordant mutations were found in plasmacytoid and corresponding conventional, glandular, or sarcomatoid areas. Co-occurring mutations in tumor protein p53 (TP53, 2 cases) and kirsten rat sarcoma (KRAS) viral proto-oncogene (1 case) were also detected. TERT promoter mutations are frequently present in PUC, which provides further evidence that TERT promoter mutations are common events in bladder cancer, regardless of histologic subtype, and supports their inclusion in any liquid biopsy assay for bladder cancer.
•Plasmacytoid bladder cancer frequently harbors hotspot TERT promoter mutations.•TERT promoter mutations are common events in bladder cancer, regardless of subtype.•Liquid biopsy assays for bladder cancer should include the TERT promoter region.
Rare circulating tumor cells (CTCs) are present in the blood of patients with metastatic epithelial cancers but have been difficult to measure routinely. We report a quantitative automated imaging ...system for analysis of prostate CTCs, taking advantage of prostate-specific antigen (PSA), a unique prostate tumor-associated marker. The specificity of PSA staining enabled optimization of criteria for baseline image intensity, morphometric measurements, and integration of multiple signals in a three-dimensional microfluidic device. In a pilot analysis, we detected CTCs in prostate cancer patients with localized disease, before surgical tumor removal in 8 of 19 (42%) patients (range, 38 to 222 CTCs per milliliter). For 6 of the 8 patients with preoperative CTCs, a precipitous postoperative decline (<24 hours) suggests a short half-life for CTCs in the blood circulation. Other patients had persistent CTCs for up to 3 months after prostate removal, suggesting early but transient disseminated tumor deposits. In patients with metastatic prostate cancer, CTCs were detected in 23 of 36 (64%) cases (range, 14 to 5000 CTCs per milliliter). In previously untreated patients followed longitudinally, the numbers of CTCs declined after the initiation of effective therapy. The prostate cancer-specific TMPRSS2-ERG fusion was detectable in RNA extracted from CTCs from 9 of 20 (45%) patients with metastatic disease, and dual staining of captured CTCs for PSA and the cell division marker Ki67 indicated a broad range for the proportion of proliferating cells among CTCs. This method for analysis of CTCs will facilitate the application of noninvasive tumor sampling to direct targeted therapies in advanced prostate cancer and warrants the initiation of long-term clinical studies to test the importance of CTCs in invasive localized disease.
Urine cytology is an essential element of the diagnostic work up of hematuria. A significant proportion of cases continue to be placed in the “atypical” or “suspicious” categories of the Paris system ...for urine cytology, posing difficulty in patient management. We report on the performance of our recently described urine-based assay “UroSEEK” in cases with equivocal diagnosis in patients who are investigated for bladder cancer. Urine samples were collected from two cohorts. The first consisted of patients who presented with hematuria or lower urinary tract symptoms (early detection cohort) and the second of patients that are in follow-up for prior bladder cancer (surveillance cohort). Urine samples were analyzed for mutations in 11 genes and aneuploidy. In the early detection setting, we found high sensitivity and specificity (96% and 88%, respectively) and a strong negative predictive value of 99%. The assay performance was less robust in the surveillance cohort (sensitivity of 74%, specificity of 72%, and negative predictive value of 53%). UroSEEK demonstrated a notable lead time to cancer diagnosis. Seven cases in the early detection cohort and 71 surveillance cases were detected at least 6 months prior to clinical diagnosis. Our results suggest a potential role for UroSEEK assay in guiding management of patients with atypical urine cytology if confirmed in future prospective trials.
Our group and others have previously demonstrated the presence of
TERT
promoter mutations (
TERT-mut
) in 60–80% of urothelial carcinomas and some of their histologic variants. Five other genes have ...been frequently implicated in bladder cancer:
FGRF3
,
TP53
,
PIK3CA
,
HRAS
, and
CDKN2A
. In the current study, we sought to determine the prevalence of mutations in
TERT
and these five other genes in de novo papillary urothelial neoplasms of low malignant potential (PUNLMP) of the urinary bladder. A retrospective search of our archives for PUNLMP was performed and 30 de novo cases were identified and included in the study. We found mutations in
TERT (TERT-mut)
and
FGFR3
(
FGFR3-mut)
to be the most common alterations in the cohort (63 and 60%, respectively). The majority of the
TERT-mut
-positive tumors (84%) had a g.1295228C > T alteration with the remaining tumors demonstrating g.1295250C > T. Approximately one fourth of tumors had TP53 mutations. These findings support the potential utility of a uniform genetic mutation panel to detect bladder cancers of various subtypes.
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